A saw wire is used for cutting Si single crystal, Si polycrystal, sapphire, SiC single crystal, and the like. As the saw wire, a free-abrasive saw wire and a fixed-abrasive saw wire are known. The fixed-abrasive saw wire has advantages that, compared with the free-abrasive saw wire, it is capable of higher-speed cutting, produces a less cutting margin loss (kerf loss), and does not easily cause environmental pollution.
The fixed abrasive saw wires include one in which diamond abrasive is fixed to a steel wire for saw wire by Ni-electrodeposition (Ni-electrodeposited saw wire), another one in which diamond abrasive is fixed to a steel wire for saw wire by resin (resin fixing-type saw wire), another in which diamond abrasive is fixed to a steel wire for saw wire by a brazing material or a solder, and the like. For example, Patent Literature 4 describes a diamond-covered wire in which a Cu-plated diamond abrasive is fixed to an Inconel 1718 wire with a Sn—Ag—Cu-based solder.
The manufacture of the Ni-electrodeposited saw wire requires a great cost. The resin fixing-type saw wire cannot provide sufficient cutting performance because the resin does not have sufficient strength for fixing the diamond abrasive. Further, the fixed-abrasive saw wire in which diamond abrasive is fixed to the steel wire for saw wire by the brazing material or the solder cannot provide sufficient cutting performance either because strength for fixing the diamond abrasive is insufficient. Here, what are important as the cutting performance are a high cutting speed, a small cutting margin loss (kerf loss), small warpage of a wafer, and the like.